Handbooks Engineering Science and Technology TIX

Global warming and climate change coincide in their main causes, the massive emission of greenhouse gases, which retain heat in the atmosphere and on the earth's surface through the so-called greenhouse effect. The generation of electricity by means of fossil fuels is an important emitter of greenhouse gases (CO2, CH4, N2O), and halogenated compounds containing F, Cl, and Br. With the purpose of contributing to the construction of viable solutions to the current energy situation of the country and in the foundation of a sustainable future, the use of solar energy for the generation of electricity by means of solar panels represents an option. The purpose of this study is to describe and control the solar cell protection material Ethylene-Vinyl-Acetate (EVA), as a contribution to the Quality Assurance of solar panels, since the function of this material is essential for the protection of solar cells, which are a vital part of the solar panel. The tests performed were: Gel content, adhesion test, and durability tests. The results obtained were within specification according to IEC 61215. From this work it is concluded that it is important to continue testing the whole process and components of the solar panels in order to guarantee the useful life of the finished product, as well as to contribute to sustainable development.

Analysis of Thermomechanical Stresses of a Photovoltaic Panel Using a Passive System of Cooling

In this paper, the gradient temperature and the thermomechanical stresses of a photovoltaic panel has been studied with and without heatsink. For this purpose, a three-dimensional analysis was carried out. Accordingly, a heat transfer analysis was developed. The numerical results show a cooling close to 26.7% with the proposed triangle fins compared with the rectangular fins studied before by another author, and the temperature distribution was determined. With this information, the stress analysis was carried out in order to find the effect on the panel due to the thermomechanical stresses. The aluminium frame was restricted to move freely. The resulting stresses field established the magnitude of the alternative stresses, resulting in a 6.7% drop compared with a reference panel. The guidelines of IEC 61215 have to be take into account. Due to the results obtained, the use of this kind of system in desert conditions is desirable because of its high operational temperature and due to the increase in heat transfer by the fins.

Effect of Wind Load on Performance of Photovoltaic (PV) Modules Available in Pakistan

Mechanical integrity of a Photovoltaic (PV) module plays a major role in its performance and electrical output. Mechanical loads which include loads produced by wind, snow, rain, and hail tend to degrade the performance of PV module by generating stresses and enhancing micro-cracks and defects. This research aims to investigate the impact of wind loads on the performance of PV modules, particularly the degradation in its power output. A load of 2400 Pa was applied as per international standards (ASTM E1830-15 and IEC-61215). A total of four PV module samples, of the same specifications with 60 W rated power, were initially subjected to solar flash testing and Electroluminescence (EL) imaging. This was followed by three cycles of mechanical load test. After the mechanical load tests, the modules were again subjected to solar flash testing and EL imaging and the results were compared. It was noted that static wind load degrades the mechanical integrity of photovoltaic modules in two ways; by aiding the propagation of existing cracks and initiating new cracks. This loss of mechanical integrity degraded the power output of PV module. Maximum drop of 2% in the power output and 0.27% in the efficiency was observed. In addition, the average increase of 3.37% in the series resistance was observed indicating decrease in performance.

The Study of Decrement in Insulation Resistance of PV String and its Effects on PV System Degradation

This paper presents the investigated variations in insulation resistances of amorphous silicon (a-Si), multi crystalline silicon (MC-Si) and hybrid solar cell (HIT). The insulation resistance of PV string of each system was measured and used to represent leakage current in photovoltaic system and the analysis was done in accordance with IEC 61215 Standard. The 10.152 kW multi-PV cell technologies grid connected system supports the energy demand of the 10 kW Building at School of Renewable Energy Technology (SERT), Naresuan University since July 2005 till date. In general the system was found effectively working under hot and humid climatic conditions of Thailand for a long duration. However the decrement in insulation resistance (MΩ) of a-Si string, MC-Si string and HIT string have affected electrical parameter of each system. The decrements in fill factor (F.F) over the 10 years period (July 13, 2005 – January 25, 2015) of a-Si, MC-Si and HIT were-27.4%, -21.9% and-6.2% respectively.